Charles’
Law
Gas law
Prepared by: Andrea Mae K. Garcia
TODAY, WE'LL LEARN ABOUT...
Know the relationship of pressure, volume and temperature.
Solve the problem using Charles’ Law
Appreciate the concept of Charles’ Law
JACQUES CHARLES (1746-1823)
• volume - temperature
relationship was named after him.
• states that at a constant pressure,
the volume of a fixed amount of
gas is directly proportional to the
Kelvin (K) temperature.
ACTIVITY
TIME!
Trial
Volume Reading
(ml)
Temperature
(˚C)
Temperature (K)
1
25
2
275.15
2
30
57
330.15
3
35
102
375.15
4
40
152
425.15
Note: To convert ˚C to K, use this formula: K=˚C+ 273.15
Why is there a need to convert ˚C to K?
Kelvin- is the basic unit for measuring temperature in the
International System (SI). “It denotes the absolute
temperature scale where by 0K or absolute zero is defined
as the temperature when molecules will have the lowest
energy”.
CHARLES’ LAW
Sample Problem:
An inflated balloon with a volume of 0.75 L at 30°C was
placed inside the freezer where the temperature is -10°C.
Find out what will happen to the volume of the balloon if
the pressure remains constant. Support your answer with
computation.
Steps in solving
using Charles’ law.
1. Write the given
2.Determine the unknown value.
3. Write the mathematical formula.
4.Cross multiplication method.
5. Rearrange the formula.
6. Multiply
7. Divide
8. Write the unknown value.
The concept of
Charles’ Law
when the temperature
increases,
the volume will also increases
and vice versa.
CHARLES’ LAW
Sample Problem:
1. At 20˚C, the volume of chlorine gas is 15dm3. Compute
for the resulting volume if the temperature is adjusted to
318K provided that the pressure remains the same?
How can you solve the problem if the unknown value
is V_1?
• V1= V2T1/T2
How about unknown value is T_2?
•T2= V2T1/V1
How about unknown value is V2?
•V2= V1T2/T1
QUIZ TIME!
CHARLES’ LAW
Solve the given problem:
A cylinder with a movable piston contains
250 cm3 air at 10°C. If the pressure is kept constant, at what
temperature would you expect the volume to be 150 cm3?
CHARLES’ LAW
Solve the given problem:
2. A tank (not rigid) contains 2.3L of helium gas at 25˚C.
What will be the volume of the tank after heating it and its
content to 40˚C temperature at constant pressure?
Assignment:
What is Gay-Lussac’s law
By: Andrea Mae Garcia